A conventional apparatus for transferring and positioning print boards will be described with reference to FIG. 1. Print boards 1 are conveyed on a conveyor 2 and are positioned at the end of the conveyor 2 by a stop 3. Each print board 1 is provided with a reference hole 4 at a fixed position spaced from the front end surface as viewed in the transfer direction, and another reference hole 5 spaced a fixed pitch from the reference hole 4.
An X-Y table 6 is provided with guides 7 for the print boards 1, such guides being provided with a vertically movable positioning pin 8 for positioning the boards 1. At a fixed position spaced from the X-Y table 6, there is provided a rotatable shaft 9 extending along the guides 7, shaft 9 having an arm 10 axially slidably and rotatably installed thereon, arm 10 being vertically swingable as the shaft 9 is rotated. Further, the arm 10 is reciprocable in the direction of arrow X by an actuator 11 located parallel to the shaft 9. The ends of the shaft 9 are provided with stops 12 for positioning the arm 10 and shock absorbers 13. Rotation of the shaft 9 is effected by an actuator 15 swinging a lever 14 fixed to the shaft 9.
The operation will now be described. The arm 10 is provided with a pin (not shown) adapted to be inserted into the reference hole 4 of a print board 1 positioned on the conveyor 2 when the arm 10 is lowered. Then the actuator 11 is operated to move the arm 10 in the direction of arrow X', and the pin feeds and positions the print board. The arm 10 is then lifted by the actuator 15, and the positioning pins 8 are inserted into the reference holes 4 and 5 by a nonillustrated separate mechanism, to fix the print board 1 in position, the arm 10 being then returned to its original position by the actuator 11.
In this case, however, because of errors in the pitch between the reference holes 4 and 5, there are times when the positioning pins 8 on the guides 7 fail to enter the reference holes 4 and 5. As measure against this problem, generally the right-hand end reference hole 5 of the print board 1 is elongated. However, when parts are to be mounted on both surfaces of the print board 1, it is necessary to reverse the print board 1. Thus, the reference holes 4 and 5 changes their positions, with the reference hole 4 after transfer operation assuming the right-hand end position, so that each time the print board is reversed the stop 3 or arm 10 must be changed in shape to adjust the pin of arm 10 to the position of the reference hole 4. Another drawback is that each time the length of the print board 1 is changed, such adjustment is necessary.
The present invention eliminates these drawbacks and makes feeding and positioning possible also when the reference hole 4 of the print board 1 is at the right-hand end, irrespective of variations in the length of the print board 1.